乳酸菌微机检索软件的开发

以现有乳酸菌信息为依据,利用汉字foxbase^＋2．10进行数据处理,研制出一套乳酸菌微机检索软件。该软件的特点：检索速度快,途径灵活,增添、修改、删除、打印方便,各模块性能优良,实用性强。     

体外重构STUB1介导α-1抗胰蛋白酶突变体Z蛋白泛素化修饰反应体系

α-1抗胰蛋白酶Z型突变体蛋白(α-1 antitrypsin Z-mutant protein, ATZ)是引发α-1抗胰蛋白酶缺陷症(α-1 antitrypsin deficiency, AATD)的主要原因,研究ATZ蛋白的泛素化修饰和降解对于治疗AATD具有重要意义。STUB1是一种重要的E3泛素连接酶,参与调节多种蛋白质的泛素化修饰。然而,STUB1是否参与ATZ的泛素化修饰尚未明确。本研究首先将ATZ和STUB1的编码基因克隆到pET28a质粒,构建了这2个蛋白的表达质粒。随后,将重组质粒转入大肠杆菌表达系统,在优化诱导条件实现了重组蛋白的异源表达。通过金属螯合亲和层析技术纯化得到目的蛋白,并通过蛋白质谱分析验证了其氨基酸序列的准确性。利用纯化的ATZ和STUB1重组蛋白,构建了一个体外泛素化修饰反应体系。实验结果显示,在ATP、E1泛素激活酶和E2泛素结合酶的协同作用下,STUB1成功催化了ATZ的泛素化修饰。本研究提供了一种体外获得Z型突变体ATZ纯化蛋白的方法,并确认了STUB1介导ATZ的泛素化修饰功能,推进了对α-1抗胰蛋白酶Z型突变体蛋白在细胞内降解过程的调控机制的理解。     

Quantitative regulation of the thermal stability of enveloped virus vaccines by surface charge engineering to prevent the self-aggregation of attachment glycoproteins

The development of thermostable vaccines can relieve the bottleneck of existing vaccines caused by thermal instability and subsequent poor efficacy, which is one of the predominant reasons for the millions of deaths caused by vaccine-preventable diseases. Research into the mechanism of viral thermostability may provide strategies for developing thermostable vaccines. Using Newcastle disease virus (NDV) as model, we identified the negative surface charge of attachment glycoprotein as a novel determinant of viral thermostability. It prevented the temperature-induced aggregation of glycoprotein and subsequent detachment from virion surface. Then structural stability of virion surface was improved and virus could bind to and infect cells efficiently after heat-treatment. Employing the approach of surface charge engineering, thermal stability of NDV and influenza A virus (IAV) vaccines was successfully improved. The increase in the level of vaccine thermal stability was determined by the value-added in the negative surface charge of the attachment glycoprotein. The engineered live and inactivated vaccines could be used efficiently after storage at 37°C for at least 10 and 60 days, respectively. Thus, our results revealed a novel surface-charge-mediated link between HN protein and NDV thermostability, which could be used to design thermal stable NDV and IAV vaccines rationally.     

Hemin with Peroxidase Activity Can Inhibit the Oxidative Damage Induced by Ultraviolet A

Excessive reactive oxygen species (ROS), a highly reactive substance that contains oxygen, induced by ultraviolet A (UVA) cause oxidative damage to skin. We confirmed that hemin can catalyze the reaction of tyrosine (Tyr) and hydrogen peroxide (H₂O₂). Catalysis was found to effectively reduce or eliminate oxidative damage to cells induced by H₂O₂ or UVA. The scavenging effects of hemin for other free-radical ROS were also evaluated through pyrogallol autoxidation, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·)-scavenging assays, and phenanthroline–Fe²⁺ assays. The results show that a mixture of hemin and tyrosine exhibits strong scavenging activities for H₂O₂, superoxide anion (O₂⁻·), DPPH·, and the hydroxyl radical (·OH). Furthermore, the inhibition of oxidative damage to human skin keratinocyte (HaCaT) cells induced by H₂O₂ or UVA was evaluated. The results show that catalysis can significantly reduce the ratio of cell apoptosis and death and inhibit the release of lactate dehydrogenase (LDH), as well as accumulation of malondialdehyde (MDA). Furthermore, the resistance to apoptosis was found to be enhanced. These results show that the mixture of hemin and tyrosine has a significantly protective effect against oxidative damage to HaCaT cells caused by UVA, suggesting it as a protective agent for combating UVA damage.     

Aerobic denitrification by novel isolated strain using NO-₂-N as nitrogen source

Biological denitrification reaction can be achieved under aerobic environment. Few aerobic denitrifiers using nitrite as sole nitrogen source were identified. Using nitrite as the sole nitrogen source, this work assessed the denitrification activity of yy7, an aerobic heterotrophic denitrifier identified as Pseudomonas sp. (94% similarity) by 16S rRNA sequencing analysis. The logistic equation describes the cell growth curve, yielding a generation time of 2.9h at an initial 18 mg l(-1)NO(-)?-N. Reduction of NO(-)?-N was primarily achieved during its logarithmic growth phase, and was accompanied by an increase in suspension pH and near complete consumption of dissolved oxygen. Three genes relating to nirK, norB, and nosZ were noted to involve in isolate strain. Isolate yy7 can survive and remove up to 40 mg l(-1)NO(-)?-N and, hence, can be applied as an effective aerobic denitrifier during simultaneous nitrification and denitrification via nitrite processes.     

基于S- 核酸酶的自交不亲和性的分子机制

自交不亲和性是一种广泛存在于显花植物中的种内生殖障碍, 可以抑制近亲繁殖而促进异交。其中, 以茄科、玄参科和蔷薇科为代表的配子体自交不亲和性是最常见的类型。这类自交不亲和性是由单一的多态性S-位点所控制。目前的研究发现这一位点至少包含两个自交不亲和反应特异性决定因子: 花柱中的S-核酸酶和花粉中的SLF(S-Locus F-box)蛋白。该文将主要介绍并讨论基于S-核酸酶的自交不亲和性分子机制的研究进展。     

CalR激活副溶血弧菌Ⅵ型分泌系统1相关基因的转录

[目的]研究副溶血弧菌群体感应(quorum sensing,QS)系统核心调控子AphA和OpaR对calR基因以及CalR对Ⅵ型分泌系统l(type VI secretion system 1,T6SS1;vp1386-1420)相关基因的转录调控关系.[方法]提取副溶血弧菌野生株(wild-type,WT)和调控...     

Protein kinase C delta null mice exhibit structural alterations in articular surface,intra-articular and subchondral compartments

IntroductionStructural alterations in intra-articular and subchondral compartments are hallmarks of osteoarthritis, a degenerative disease that causes pain and disability in the aging population. Protein kinase C delta (PKC-δ) plays versatile functions in cell growth and differentiation, but its role in the articular cartilage and subchondral bone is not known.MethodsHistological analysis including alcian blue, safranin O staining and fluorochrome labeling were used to reveal structural alterations at the articular cartilage surface and bone–cartilage interface in PKC-δ knockout (KO) mice. The morphology and organization of chondrocytes were studied using confocal microscopy. Glycosaminoglycan content was studied by micromass culture of chondrocytes of PKC-δ KO mice.ResultsWe uncovered atypical structural demarcation between articular cartilage and subchondral bone of PKC-δ KO mice. Histology analyses revealed a thickening of the articular cartilage and calcified bone–cartilage interface, and decreased safranin O staining accompanied by an increase in the number of hypertrophic chondrocytes in the articular cartilage of PKC-δ KO mice. Interestingly, loss of demarcation between articular cartilage and bone was concomitant with irregular chondrocyte morphology and arrangement. Consistently, in vivo calcein labeling assay showed an increased intensity of calcein labeling in the interface of the growth plate and metaphysis in PKC-δ KO mice. Furthermore, in vitro culture of chondrocyte micromass showed a decreased alcian blue staining of chondrocyte micromass in the PKC-δ KO mice, indicative of a reduced level of glycosaminoglycan production.ConclusionsOur data imply a role for PKC-δ in the osteochondral plasticity of the interface between articular cartilage and the osteochondral junction.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0720-4) contains supplementary material, which is available to authorized users.     

Pyrosequencing Reveals Contrasting Soil Bacterial Diversity and Community Structure of Two Main Winter Wheat Cropping Systems in China

Microbes are key components of the soil environment, playing an important role in maintaining soil health, sustainability, and productivity. The composition and structure of soil bacterial communities were examined in winter wheat–rice (WR) and winter wheat–maize (WM) cropping systems derived from five locations in the Low-Middle Yangtze River plain and the Huang-Huai-Hai plain by pyrosequencing of the 16S ribosomal RNA gene amplicons. A total of 102,367 high quality sequences were used for multivariate statistical analysis and to test for correlation between community structure and environmental variables such as crop rotations, soil properties, and locations. The most abundant phyla across all soil samples were Proteobacteria, Acidobacteria, and Bacteroidetes. Similar patterns of bacterial diversity and community structure were observed within the same cropping systems, and a higher relative abundance of anaerobic bacteria was found in WR compared to WM cropping systems. Variance partitioning analysis revealed complex relationships between bacterial community and environmental variables. The effect of crop rotations was low but significant, and interactions among soil properties, locations, and crop rotations accounted for most of the explained variation in the structure of bacterial communities. Soil properties such as pH, available P, and available K showed higher correlations (positive or negative) with the majority of the abundant taxa. Bacterial diversity (the Shannon index) and richness (Chao1 and ACE) were higher under WR than WM cropping systems.